Process for fractionating compound substances containing ingredients of closely-related solubility



UNITED STATES PATENT OFFICE.

ARMIN SEIDENBERG, OF NEW YORK, N. Y.

PROGESS FOR FBACTIONATING COMPOUND SUBSTANCES CONTAINING INGREDIENTS 0F CLOSELY-RELATED SOLUBILITY.

1,340,136.- lio Drawing.

To all whom it may concern:

Be it known that I, ARMIN SEIDENBERG, a citizen of the United States, residing at the city,-county, and State of New York, have invented a certain new and useful Process for Fractionating Compound Substances Containing Ingredients of Closely-Related Solubility, of which the following is a specification.

My invention relates to a method of separating compound substances, such as fats,

by taking advantage of the differences in solubility existing among their constituent parts.

When the ingredients to be separated are closely related in solubility, such as the various glycerids that constitute the vegetable or animal fats, or the individual members of the paraifin series that constitute many mineral oils, considerable difficulty has heretofore been experienced in making separations even into groups, without including appreciable quantities of other groups.

The principal object of my invention is to provide a process whereby the constituent parts may be more easily and completely separated than by any method, entailing the use of solvents, heretofore known or used.

According to my invention, I separate the parts or ingredients by first dissolving the substance in a solvent composition containing components of different. degrees of solvent action, and then gradually and uniformly removing said components from the solution in the general order of their solvent action on the ingredients to be separated.

The conditions which are required for securing the best results are the most minute gradation attainable in the diiferentlation.

to be effected between the different ingredients or parts to be separated, and as wide and instantaneous a uniformity of action throughout the entire solution as is posslble, so that the proximate points that i nd1cate the greatest condition of insolubihty for 1 each ingredient or constituent part of the compound. substance may be approached, one after the other, with as l1ttle overlap-' ping as possible, and at the same time 11111- formly throughout the solution. It is the.

aim of the method herein described to ac- -,complish thisto as great an extent as possible.

Specification of Letters Patent. P t t May 13, 1'92 Application filed August 10, 1918. Serial No. 249,260.

In carrying out my invention I dissolve the compound substance to be fractionated 1n a solvent composition containing two or more components of different degrees of solvent action and volatility.

The components are usually, though not necessarily always, miscible in each other. If desired the composition may contain, in

addition to the solvent components, a com- -volatilization or otherwise in the general order of their solvent action on the ingredients or parts to be separated. In this way the ingredients or parts will be separated in the inverse order of their solubility, that is to say, the least soluble ingredient orpart will be precipitated or "thrown out of solution first and so on.

The solvent components are preferably removed from the solution by passing, either by increased or reduced pressure (or suction), a current of air or other gas through the solution at an approprlate rate of speed. Other suitable means such as, for example,

' reduction of pressure alone or mechanical agitation of the solution or combinations of these or other means may be employed for removing the solvent components.

ince, as is well known, the vaporization of a liquid produces a reduction 1n 1ts temperature, it is possible by using a low bolling point liquid to secure a very low temperature. By regulating the speed of removal, this may be attained as gradually as may be desired. The extent of the temperature decrease may, if desired, be regulated, although not finely graded, by means of an outside temperature control.

Itis also well known that the extent of the solubility of the great majority of substances in various solvents, decreases with a decrease in the temperature of these soluniform volatilization of the solvent components. By this means, at any instant of time, a very minute amount of solvent is removed simultaneously and uniformly from every part of the solution and a very minute decrease oft'emperature takes place simultaneously and uniformly in every part of the solution. Due to this the ingredients of the dissolved substance will be separated with the greatest possible degree of refinement and with the least possible overlap-.

ping, since the condition of increasing insolubility (of the various ingredients) is progressively produced and as gradually and uniformly as is possible under the conditions.

During the process of removing the more volatile component or components, the less volatile component or components are usually also removed to a slight extent. When all or almost all of the first mentioned component or components has been removed the remainder of the solvent can also be removed by continuing the process until the entire amount of substance held in the solution has again been thrown or separated out.

The method may also be applied to a series of non-miscible solvents that on being allowed to rest will form into separate zones. Combinations of this type may be secured either at the start or as a result of the removal in part or entirely of one or more of the components used assolvents. In this case the various ingredients to be separated are divided among the various zones according to their relative solubility in those zones, and the proportion and amount of dissolved substance in any zone may be regulated, as already described, by removing therefrom the more volatile component.

As aspecific example of a solvent composition that may be used to fractionate the ingredients or parts of a fat, such as tallow, may be cited a composition of ethyl alchohol and ethyl ether. The molten tallow is dissolved in a mixture ten times its volume, consistin of ethyl ether and ethyl alcohol (absolute in equal proportions. If necessary the solvent is warmed slightly to secure complete solution and then allowed to cool again. Any solid matter that settles out on cooling is filtered ofi by any of the usual methods as residue A. The filtration should be thorough. and as 'much of' the sglvent as possible removed from the res- 1 ue.

Through -the liquid solution. air is thenasplrated until the liquid is reduced to about one-half its original volume; The precipilayers each of which is entirely clear. These are now siphoned off from each other. The upper liquld layer leaves practically no residue on evaporating off the volatile portion. The lower layer on removing the volatile solvent by evaporation contains practically all the remaining fatty material (residue C). By combining residue A and residue B, practically all solid fat in the tallow can be obtained, while practically all 'of the liquid fat will be contained in residue C. This latter is the portion in tallow of most value in the manufacture of oleomargarin. By refractionating each of these fractions in the manner described, they can be further purified.

While in the foregoing description the solvent composition has been considered as composed entirely of liquids, it may also contain substances which at ordinary atmospheric temperatures are gases or solids.

Theingredient or constituent tobe separated from the solution may be thrown out or precipitated in the solid or liquid state,

or it may be separated by forming as a re- 1 sult of the process, a liquid zone distinct from the rest of the solution with part or parts of the components forming the solvent composition, or otherwise .it may be secured by being dissolved or abstracted by a zone already formed at the start by a change effected during the process in the zone in whlch it was originally dissolved;

What I claim is:

1. A process of'fractionating a compound substance containing ingredients of closely related solubility which consists in first dissolvmg the substancein a plurality of solvents of different degrees of solvent action and volatility, said solvents being of such character that those having the greatest solvent action on the least soluble ingredient or ingredients are the most volatile and those havlng the least solvent action on said ingredlent or ingredients are the least volatile, and then gradually volatilizing the solvents so as to preclpitate or-separate the ingredients 1n the lnverse order of their solubility.

2. A process of fractionating a compound substance containing ingredientsof closely related solubility which consists in first forming a solution by dissolving the substance in a composition containing components of difierent degrees of solvent action and volatllity, said components being of such solvent action on the least soluble ingredient or ingredients are the most volatile and those having the least solvent action on said ingredient or ingredients are the least volatile, and then passing a current of gas through the solution so as to agitate it and to gradually and uniformly reduce the temperature of the solution and to gradually and uniformly volatilize the components of the solvent composition, whereby to gradually and uniformly precipitate or separate the ingredients in the inverse order of their solubility.

3'. A process of fractionating a compound substance containing ingredients of closely related solubility which consists in first dissolving the substance in a plurality of solvents of different degrees of solvent action and volatility, said solvents being of such character that those having the greatest solvent action on the least soluble ingredient or ingredients are the most volatile and those having the least solvent action on said ingredient or ingredients are the least volatile, and then allowing the solvents to evaporate accompanied by agitation, so as to gradually and uniformly reduce the temperature of the solution whereby to gradually and uniformly precipitate the ingredients in the inverse order of their solubility.

ARMIN SEIDENBERG.

-Witness:

W. J. HEFFERNAN. 

